1. Field of the Invention
The present invention relates to a thin film magnetic head comprising bumps, and a manufacturing method therefor.
2. Description of the Related Art
A thin film magnetic head comprises an electrode section for supplying a current to a coil layer for inducing a recording magnetic field between upper and lower core layers, and to a magnetoresistive element for detecting a leakage magnetic field from a recording medium. The electrode section comprises lead conductor layers conductively connected to the coil layer and the magnetoresistive element, electrode pad layers for external connection, and bumps for conductively connecting the lead conductor layers to the electrode pad layers. The electrode section is conventionally formed by the process described below.
First, the lead conductor layers conductively connected to the coil layer and the magnetoresistive element are formed, and a conductive protective layer is formed in a region of the lead conductor layers, in which each bump is to be formed. Next, the bumps each having an umbrella sectional shape are formed on the conductive protective layers, and an insulating protective layer composed of alumina or silicon dioxide is formed over the entire surface including the bumps. Then, the insulating protective layer is polished to expose the tops of the bumps, and the electrode pad layers composed of a conductive material such as Au or the like are formed on the bumps. In this manner, the electrode section is formed.
However, as shown in FIG. 16, the above-described conventional manufacturing method has the problem of producing portions (spaces γ) without an insulating protective layer 20′ on both sides of a conductive protective layer 15′. Such spaces γ cause corrosion of a bump 16′ with a polishing solution which gathers at the time of a polishing work for exposing the top of the bump 16′. Therefore, the bump 16′ becomes non-conductive, and thus a current cannot be supplied to a coil layer and a magnetoresistive element through a lead conductor layer 10′.